Optical control of sunlight at window and door openings with controlled positioning of composite transparent materials to eliminate glaring sunlight rays while providing normal daylight illumination



Aprll 15, 1969 B. I. SEEGER 3,438,699

OPTICAL CONTROL OF SUNLIGRT AT WINDOW AND DOOR OPENINGS WITH CONTROLLEDPOSITIONING OF COMPOSITE TRANSPARENT MATERIALS TO ELIMINATE GLARINGSUNLIGHT RAYS WHILE PROVIDING uonmm DAYLIGHT mwmmmon Filed Oct. 21, 1965Sheet of2 IN VEN TOR.

A TTORNE V Aprll 15, 1969 ,1, SEEGER 3,438,699

QOPTICAL CONTROL OF SUNLIGHT AT WINDOW AND DOOR OPENINGS WITH CONTROLLEDPOSITIONING OF COMPOSITE TRANSPARENT MATERIALS TO ELIMINATB GLARINGSUNLIGHT RAYS WHILE PROVIDING NORMAL DAYLIGHTILLJUMINATION Filed Oct.21, 1965 Sheet 3 of 2 ONE OF n E-QUAYL SPACES L 4" Y Z6 OTOT' z. oo" 083. 02

1N VENTOR. aim 4R0. I. 55565? .4 TTORIVE Y United States Patent3,438,699 OPTICAL CONTROL OF SUNLIGHT AT WINDOW AND DOOR OPENINGS WITHCONTROLLED POSITIONING OF COMPOSITE TRANSPARENT MATERIALS TO ELIMINATEGLARING SUN- LIGHT RAYS WHILE PROVIDING NORMAL DAYLIGHT ILLUMINATIONBernard I. Seeger, 1600 SW. Dawson St., Seattle, Wash. 98106 Filed Oct.21, 1965, Ser. No. 499,962 Int. Cl. G02b 27/38 US. Cl. 350-263 7 ClaimsABSTRACT OF THE DISCLOSURE An adjustable multiple slat assemblyassembled in a configuration similar to a Venetian blind is used tocontrol glaring rays of sunlight through selectively changing angularadjustments without otherwise interfering with daylight illumination ofa space, each slat being a composite subassembly of at least twotransparent pieces of material having interfitting smooth surfacedridges or prisms and otherwise smooth even outer surfaces.

This invention relates to transparent material assemblies used tocontrol sunlight and primarily to avoid its direct glare. Moreparticularly, in one preferred embodiment, such an assembly comprisescomposite transparent materials arranged as adjustable slats of aVenetian blind.

The purpose of the invention is to control sunlight and its glareeffects with transparent material assemblies which at all times continueto pass suflicient quantities of indirect daylight for continued activeuse of the space beyond any slat assembly without having to resort toartificial lighting.

The invention, briefly described in reference to a preferred embodiment,comprises vertical or horizontal blind arrangements of multiple slatswhich are collectively moved and positioned to fully intercept the glarerays of the sun, with each slat being a composite subassembly of atleast two transparent pieces having intermeshing smooth ridges or prismsand otherwise smooth even outer surfaces.

This invention is illustrated in the accompanying drawings, wherein: 7

FIGURE 1 is a perspective partial sectional view of a window in a homeor office with a preferred horizontal blind of transparent materialsarranged at a neutral position; a conventional controlling and holdingstrap being indicated in dotted lines;

FIGURE 2 is a perspective sectional view showing in part theinstallation of a vertical blind of transparent materials arranged at aneutral position, no conventional controlling and holding mechanismbeing indicated, nor conventional sectioning lines being used in theslats for clarity;

FIGURE 3 is an end view of one of two like transparent pieces orsegments used in each slat of either the vertical or horizontal blind;

FIGURE 4 is an end view of two like transparent pieces or segments, asshown in FIGURE 3, fitted together as a slat of either the vertical orhorizontal blind.

FIGURE 5 is an enlarged partial end view of two like transparent piecesor segments, as shown in FIGURE 4, with dotted lines indicating whathappens to selected light rays A, B, and C when discriminatelycontrolled by such a respective slat; the slat being arranged so sunglare light rays approach the first outside smooth transparent slatsurface preferably at ninety degrees or within an allowable tolerancedepending on the transparent materials being 3,438,699 Patented Apr. 15,1969 "ice used, such as 4 /2 degrees to either side of the normal, whencertain plastic slats are assembled, as illustrated.

Referring to FIGURES l and 2, the illustrated embodiment of thisinvention is directed to providing vertical 10 or horizontal blinds 12of transparent materials 14 to optically control sunlight at window orlike openings 16. The materials used are highly transparent to allvisible light, However, these materials are generally shaped asindicated in FIGURE 3 to exclude light and heat rays coming from aparticular direction which is generally in line with the position of thesun.

In reference to the utilization of a transparent polymethyl methacrylatematerial, having a refractive index of 1.49 a preferred construction ofa segment 18 or 20 of the two segment slat 22 is shown in this FIGURE 3.A two inch segment or strip, having a length equal to the height orwidth of a window opening 16, is made from near 0.107" stock. Multiple Vridges or prisms 26 at a included angle are made leaving an unmodified0.02" thickness 28 with all resulting surfaces being or appearing asbeing polished.

The dimensions shown in FIG. 3 are arbitrary rather than unique, andwere chosen for compatibility with present suspension and adjustmentmechanisms. The 45 x 90 prism pattern is also arbitrary, but uniquelyprovides a totally reflective zone symmetrical with respect to thenormal, and rejects the direct sun rays backward toward the sun, withminimized annoyance to persons outside of the protected building area.

Two of these like strips, segments or pieces 18, 20 are oppositelyoriented and placed in contact with each other to form a rectangularcross-sectioned slat 22 as illustrated in FIGURE 4. The ridges orprisms26 are left immersed, so to speak, in a very thin medium, preferably airor vacuum, having a refractive index suitably lower than that of thetransparent material. The like strips 18, 20 are only mechanicallyfastened as necessary at spaced locations (not shown) and preferablycontinuously bonded about the periphery.

The multiple arrangement of these slats 22 may be undertaken by any ofthe conventional ways already well known as suggested by dotted lineillustration of a strap 24 in FIGURE 1. Preferably, the movement of oneslat 22 by controls (not shown) will move all slats 22 to confront theglare rays which may be coming directly from the sun, reflected from awater surface, glass surface of an adjacent building, etc.

The successful control of sunlight or other glare rays of extremeintensity and the simultaneous control of less intense and indirectlight is illustrated in FIGURE 5. A portion of a slat is enlarged inthis FIGURE 5 to illustrate what occurs in reference to three selectedlight rays.

Ray A coming as an incident light ray Ai, comes from a direction withina tolerance range of 4 /2 degrees either side of the normal, N, whichmay be considered also as the direction of the sun S. Any ray like ray Ain this tolerance range of 4 /2 for the plastic material illustratedwill be totally reflected externally both avoiding the glare andreducing the possibility of any substantial radiant heat increasesinside a room beyond the window opening which would otherwise be causedby these glare rays of high intensity.

Ray B, coming as an incident light ray Bi is passed through as ray Bp,without net deviation, thus emerging in its original direction.Similarly, an occupant of the protected interior space has a clear andundeviated view out- .ward along line of such a ray. Such rays as B andthose prism face X which has a slope of opposite sense to the raydirection.

Ray C, coming as an incident light ray Ci, encounters, however, anoblique prism face which has a slope of similar sense to the raydirection. As a result, these rays, similar in relative direction andlocation to ray C are trapped throughout successive internal totalreflections within the parallel faces of the resulting slat. Thetrapping of these rays Ct, causes the appearance of opaque bands oropaque view ranges which are alternately spaced with the clear viewranges or clear bands, when viewed from the interior of a room lookingat the slat in a direction opposite to the direction of a ray C.

The appearance of these clear and opaque view bands or ranges inreference to their relative widths will vary when viewed from theinterior of a room in different locations. However, at all times glarerays are totally reflected and cannot be viewed from within the interiorroom. This remains true providing that over a period of time, the groupof slats are caused to confront or to track direct sunlight and therebyremain capable of total reflection of A rays.

Therefore, by construction of slats in this way or similar thereto fromtransparent materials having refractive indices equal to or greater thanthe square root of two, and by control of their collective movement withchanges in the location of high intensity glare rays coming from anindirect source such as a lake surface or directly from the sun, areeffectively eliminated by total reflection while other less intenselight energy is skillfully provided in places beyond the location ofsuch transparent slats.

I claim:

1. A transparent material assembly to optically control sunlight,especially its direct glare rays, while continuing to pass other rays toallow active use of space beyond such transparent material assemblywithout resorting to artificial lighting, comprising:

(a) conventional Venetian blind positioning devices adapted to hold andto pivot multiple slats of the said transparent materials across an areabeing subjected to direct sunlight; and

(b) multiple slats of transparent materials fitted in part into thepositioning devices for adjustment to pre vent passage of glare rays ofsunlight through the sunlight area, each slat, comprising, at least, twotransparent pieces having intermeshing smooth ridges forming prisms andotherwise smooth even outer plane surfaces.

2. A transparent material assembly to optically control sunlight, asclaimed in claim 1, wherein said intermeshing smooth ridge prisms areequal sided.

3. A transparent material assembly to optically control sunlight, asclaimed in claim 2, wherein said two pieces are a very slight distanceapart along their near mating complementary smooth ridges that form thenearly com plete resulting intermeshing prism slot structure.

4.-A transparent material assembly to optically control sunlight, asclaimed in claim 3, wherein the said two pieces are formed from atransparent polymethyl methacrylate material.

5. A transparent material assembly to optically control sunlight, asclaimed in claim 3, wherein the said two pieces are continuously bondedonly about their resulting periphery.

6. A transparent material assembly, to optically control sunlight, asclaimed in claim 5, wherein said transparent materials used have arefractive indices of the square root of two and greater.

7. A transparent material assembly to optically control sunlight, asclaimed in claim 6, wherein each said transparent piece is made from astock piece which is initially rectangular in cross section, being 0.107inch thick and 2 inches wide and as long as one dimension of thesunlight area, with eleven and one half equal spaces References CitedUNITED STATES PATENTS 11/1933 Higbie 350-263 7/1961 Vetere 350263FOREIGN PATENTS 562,077 10/1932 Germany. 429,340 5/1935 Great Britain.

JULIA E. CORNER, Primary Examiner.

US. Cl. X.R.

